Detonation responsive means for controlling internal-combustion engines



Sept. 17,1946. 1 P. J. cos'r 2,407,652 DETONATION RESPONSIVE MEANS FOR CONTROLLING V INTERNAL-COMBUSTION ENGINES 7 Original Filed June 6, 1942 2 Sheets-Sheet 1 Ill IH ENGINE MITTER HQ. 2 c' nauasrog FIGS MIIIELI haze! 46 CONTROL UNIT ' INVENTOR. PHILIP J. COSTA mmcxrea g 2 a 4 Sept. 17, 1946. P. J. cosTA 2,407,652

DE'IONATION RESPONSIVE MEANS FOR CONTROLLING INTERNAL-COMBUSTION ENGINES Original Filed June 6, 1942 2 Sheets-Sheet 2 FIG. 4

INVENTOR PHILlP J. COSTA Patented Sept. 17, 1946 DETONATION RESPONSIVE MEANS FOR CONTROLLING INTERNAL-COMBUSTION ENGINES Philip J. Costa, Franklin Square, N. Y., assignor to Sperry Gyroscope Company, Inc., Brooklyn, N. Y., a corporation of New York Continuation of application Serial No. 446,070,

June 6, 1942.

1944, Serial No. 524,170

20 Claims.

. 1 This invention relates to detonation responsive means for controlling an internal combustion engine. More particularly the invention is concerned with a detonation responsive system which includes a device for transmitting cyclic movements of variable duration to known instrumentalities for controlling the operation of an internal combustion engine. While the improved system is useful in the elimination of the occurrence of detonation in the cylinders of any internal combustion engine, it is particularly adapted to be employed with aircraft engines in which the relatively thin cylinder walls are subject to severe damage or complete destruction under such conditions. This application is a continuation of my copending application S. N. 446,- 070, filed June 6, 1942.

The principal object of the present invention is to provide an automatically operative system by which the time interval between recurrences of detonating or knocking engine conditions is effectively and controllably delayed.

One of the important features of the invention resides in the'provision of a combined manual and automatic system for controlling the ratio of the fuel to air mixture being utilized by the internal combustion engine.

Another feature of the invention is provided in the combination of elements included in the system which cooperate to obtain the desired result and consist of an internal combustion engine, a means for controlling the working conditions of the engine such as the carburetor or ignition timing control device, a detonation pick-up transmitter or means for detecting detonation in the cylinders of the engine and the means or device included in the system which is operable in response to the detonation detecting means.

Other objects, features and structural details of the invention will be apparent from the following description when read in connection with the accompanying drawings, wherein;

Fig. 1 is a schematic view and wiring diagram inwh'ich the preferred form of the invention is illustrated.

Fig. 2 is a detail view showing the system employed to control the engine by means of an ignition timing device.

Fig. 3 is a further detail view showing the system employed to control the engine by means of an additional or auxiliary fuel supply valve.

Fig. 4 is an enlarged vertical section showing in detail the internal construction of the rocker type of control unit included in the improved This application February 28,

2 detonation responsive system 1, and.

Fig. 5 is an elevation view of the control unit illustrated in Fig. 4 showing the fixed type of control unit employed in Figs. 2 and 3.

With reference particularly to Fig. 1, the detonation responsive system is shown to include an internal combustion engine of the radial cylinder type employed in aircraft which isoutlined schematically and indicated at N. The carburetor and the air intake tube for the same are desig illustrated in Fig.

nated at II and I2, respectively. These parts being of conventional construction are also shown schematically. The means for controlling the working conditions of the engine may cooperate to regulate any portion of the engine operable to suppress detonation, typically as outlined in Van Dijck Patent 2,220,558. The regulator is herein illustrated, by way of example, as the usual fuel mixture control on carburetor H having the usual throttle arm l3 which may control a throttle valve (not shown) of the butterfly type. This valve provides a means of controlling engine speed or power output by regulating the air-flow to the cylinders. The throttle control determines the speed at which the crank shaft of the engine is revolved, and by a direct linkage .(not shown) to the arm the same is positioned manually in a desired manner by the pilot links-45 and I5, and adjustable lever l6 located in the cockpit of the craft.

On most high-powered engines the mixture of fuel to air supplied the engine is regulated by limiting the amount of fuel vaporized in the air intake tube [2. By a suitable detent and stop construction usually provided within the carburetor, the arm l4 may be positioned in any one of four operating positions, shown at the dial indications in the cockpit of the craft, with reference to the settable lever Iii, as full rich, auto-rich, auto-lean and idle cut-off, by manual manipulation of the pilot. Provisions of this nature may or may not be incorporated in the improved detonation responsive control system. Such an arrangement, having proven satisfactory, is provided for in the instant case by a relatively fixed holding piece I! having four notche in the under-surface of the same and a spring urged detent 18 that engages the notches. Deten-t I8 is situated on a vertical arm l9 which extends from the casing of the control device or unit 23 which itself, in this instance, is mounted to rock about a fixed pivot point 2!. Link I5 is pivotally connected to the end of the rod of a piston element contained within the unit 20, and hereinafter more particularly described. Also, link I5 is pivotally connected to the casing of the unit 25] so that the unit is included as an integral portion of the linkage system by which the valve positioning arm 14 is controlled. Arm It may be termed the gas to air mixture control in this embodiment of the invention.

With respect to the various positions in which the linkage system may be manually set by the pliot, it may be considered that when the craft takes off the throttle of the carburetor is fully open and the mixture control is set at full rich position until the craft is at a safe height above surrounding obstacles. If the craft is still climbing, the pilot can then set lever it to the autorich position which moves arm M to open the valve slightly. The valve, in turn, permits less fuel to be vaporized in theair tube l2, thus decreasing the richness of thefuel toair mixture entering the cylinders. Throttle arm [3 is moved independently of the lever lt'and is adjusted as desired by the pilot. When the craft reaches a desired altitude and is traveling under normal straight flight conditions, the engine may be adjusted to obtain maximum economy of operation by-setting the mixture lever to. the auto-lean position. As the economy of operation of the prime mover is increased, the frequency of occurrence of detonation in the cylinders of'the same also increases so that due to engine failures and the inability to determine a safe operating point above that providing most economical operation, the pilots have been warned by engine and carburetor manufacturers against the danger in usingthe auto-lean position. With the present system, the mixture control lever can be safely set in the auto-lean position and an indicator observed to ascertain the frequency of occurrence of; detonation in th engine. If such occurrences appear too frequently or are heavier in nature than desired, the position of the relative fixed holding piece ll may be changed slightly by a suitable adjustmentand the mixture arm reset to slightly enrich the ratio, of fuel to air being supplied the engine to maintain detonation below a predetermined maximum level of severity. In this manner, the prime mover may be controlled to, obtain the greatest operating economy consistent with engine safety, When in the idle. cut-off position the mixture valve, by special internal design, actually closes again to. richen up the, mixture, even though the-lever is put into a diiferent position.

Further, with reference to Fig. 1, each of the cylinders of the internal combustion engine is provided with a means for detecting detonation, one of such detonation'pickeup transmitters being indicated at 22. This transmitter which isillustrated schematically in the drawing may be of the type particularly described in U. S. Letters Patent No. 2,275,675, issued March 10, 1942, to C. S; Draper et al. The output of the transmitter may be fed to a suitable amplifier indicated schematically at 23 by way of leads Z4. The amplifier is energized from a suitable source of electrical energy (not shown) and the output of the same may be employed to illuminate a neon tube indicator 25 situated in the cockpit of the craft, the circuit leads for this purpose being shown at 2 6 A separate circuit-closing relay 21 of conventional construction may also be energized by' the output of the amplifier 23 by way of leads 28. The automatic detonation contro1 unit is in- Ql de in. h rcuit complete b the relay in this instance, the circuit being energized by a suitable source of'energy such as battery 29.' If desired, the control unit 20, hereinafter more particularly described could be actuated directly by the output of the schematically shown detonation pick-up transmitter 22 thereby obviating the use of the relay 2! and the independent circuit which the same closes upon occurrence of detonation in any of the cylinders of the prime mover. As

' shown in Fi l, the single flexible cable so includes separate leads for completing the circuit containing the relay 21, source 29 and control device or unit 29. It will be understood from the foregoing description that operation of the system is effected by the detonation pick-up transmitter 22 which transforms the high frequency vibrations in the cylinder in which detonation is occurringinto, electrical impulses. These pulses are amplified in the instant caseby means of amplifier 23 and the output of the amplifier is utilized to. both effect illumination of the indicator 25; and close the relay 2'! controlled circuit. which includes the, in thi instance, pivotally mounted control unit 29. Bysuitably controlling the sensitivity of the amplifier 23, the pick-up transmitter may be rendered as sensitive as; desired. Both the control unit and indicatorof the system are preferably rendered, operable upon that approach of detonating conditions in-thecylinders of the engine known as incipient dot-,

onation, characterized by several occurrences per minute and not apparently harmful to engines;

even for prolonged periods.

With particular reference to Figs. 4 and 5, the illustrated control unit or device 20 is shown in the form of a cylinder element havinga casing 3i and end walls 32 and 33. In Fig; 4, the cylinder element is divided into two fluid containing compartments 3.4 and 35 by a fixed central wall 36 and a solenoid or coil 31 having a side defining plate 3,8. The solenoid 3'! is included in the relay controlled circuit whose cable 30 is fixed, to the casing 3| by a suitahle connection, A piston member for the cylinder element is indicated at 40., the same defining one wall of the compartment 35. This piston performs the function of an actuating member for the control unit to automatically position the instrumentalities employed in controlling the working conditions of operation of the internal combustion engine. In the rockertype control unit in Fig. 4, such controlling movementisimparted to lever I5 byway of the iston rod 4,], for piston Ml.v A. Spring 42" or other suit.-. able means is effective to restore the piston ac, tuatingmember to, a normal or initial position against stops d3 situated on the face of fixed dividing wall 36. In the form of the control unit shown in Fig. 5, the casing 3| is suitably mounted in a fixed position on a bracket piece 46.

In both of' the types of' control units 20 shown in the drawings, the solenoid 31 provides a partof the electromagnetic means employed foreffecting unidirectional movement of the fluid to the piston member wall defining compartment. 35 to cause movement of the piston actuating member. It will be understood that this result occurs in response to energization of the solenoid when the relay controlled circuit is closed by the detection of detonation at the. pick-up. transmitter. A hollow electromagnetic core piece 48 of cylindrical form cooperates with the solenoid and is mounted for axial movement within a cylindrical wall defining element 43 whose longitudinal axis is arranged in coaxial relation to the central axis of the solenoid. The core piece 48 has a valve-controlled passageway 50 therein, the valve being represented in the form of a ball 5| which is normally pressed against its seat. by aspring 52 situated within the hollow core 48. The electromagnetic plunger or core 43' is positioned within the cylindrical wall defining element 49 by means of a spacing spring 53, which the plunger 48 compresses when it moves through influence of the energized solenoid, and an opposing spring 53. The extent of axial movement permitted the core is defined by a stop, as.

indicated. at 54, situated at the end of a hub piece on the central wall 36.

VA valve-controlled passageway is included in the structural provisions shown in the drawing for connecting the interior of the fluid. containing chamber defined by the cylindrical wall 43 and the chamber 35. In this instance, this construction is provided by valve plate 55, valve ball 56 and the open ended, screw-threaded plug 51. A spring 58 normally holds the valve ball 56 against its seat in the valve plate 55. Compartments 35 and 34 are connected by a passageway 59 situated in the wall of the casing 3!. An adjustable valve element 5!] is located in a position in the casing 3| to restrict the flow of fluid passing from compartment 35 to compartment 34. In addition to passageway 59, a further passagewayis provided in the wall of the casing 3|, as indicated at 6|, the same connecting the area 34' of the cylindrical casing to the rear of the piston member 40 to compartment 34. There is no valve situated in passageway 6! so in effect the connected compartments 34 and 34 form a single compartment. The end of the passageway 6| in the wall of the cylinder element 3| adjacent compartment 34' is of sufiicient longitudinal dimensions, the same being formed of greater length than the thickness of the piston member 40, to provide an operative positionlimit for the movement of the piston member within the cylinder element. This position is indicated by the dotted line position of the piston member 40 in Fig. 4, in which the passageway BI is shown as directly connecting both compartments 35 and 34. The entire cylinder element 3i is preferably filled with a fluid such as oil and a pressure responsive means such as bellows unit 62 is provided for the structure, the same compressing upon expansion of the fluid due-to temperature changes and expanding upon shrinkage in the volume of fluid when the temperature condition affecting the device causes such to occur.

In operation, the energized solenoid 31 of this unit effects movement of the magnetic core 48 to the left, as viewed in Fig. 4, against the action of spring 53. A portion of the fluid within the chamber defined by the cylinder wall 49 and the interior of the hollow core 48 is consequently forced-past the valve ball 56 into the compartment 35. Valve ball 55 permits unidirectional movement of the fiuid into the compartment 35 only, such movement resulting in displacement of the piston member 40 and consequent suppression of detonation, e. g. by movement of the mixture control arm of the carburetor. This, in turn, causes enrichment of the fuel mixture supplied the engine by the carburetor to automatically change the operating conditions of the engine so that detonation is overcome. The solenoid 3'1 is energized by the detonationpick-up 6 transmitter 22 for each, of the cylinders of the engine and generally causes a number of pulsating movements of the core 48, each movement efiectingdisplacement of the piston member over a predetermined minor portion of the full operating range of the piston. When thesolenoid is no longer energized, the return movement of the control device occurs underinfluence of the spring 42, the fluid being forced to return to the compartment 34, under normal circumstances, by way of passageway 59 which contains the adjustable valve 60, operating as an escapement to delay the return movement. On each return movement of the core 48, fluid from the compart-' ment 34 is admitted to the chamberdefined by the cylindrical wall member 49 and the interior of the hollow core 48 by way of the unidirectionally acting valve controlled by spring-loaded ball 5!. The adjustable valve 53 provides a means for regulating the duration of the return movement affected by the control unit which functions as a cyclic actuating means having initiating and returning movements. In the combined manual and automatic control system illustrated in Fig. 1, .the automatic mixture controlunit functions when necessary upon occurrence of detonation in the cylinders of the engine at either manual position 2 or 3, it being presumed that no detonation will occur at either of the.

other manual settings for the system. When operative, the device functions to enrich the fuel to air mixture supplied the engine u'ntil detonation ceases, after which it slowly restores the system to the original conditions of operation at which the same was manually set by the pilot. It is apparent that by setting valve 60, as desired, the duration of the restorative portion of the cyclic actuating means may be extended to approximately control cyclic recurrence of detonation in the engine atsuch spaced intervals as to provide safe operation of the craft at the auto-lean mixture setting. Incipient detonation of the order of several occurrences per minute may be maintained steadily when the return movement of the piston requires somewhat over 10 seconds. Normal operation of the automatic control system thus is indicated by several flashes perminute on the signal device or indicator 25. Rapidly recurring flashes definitely indicate trouble in the automatic control, and warn the operator to shift the manual control lever l6 as an emergency measure in a direction to suppress detonation, e. g. byenriching the fuel mixture. It will be apparent that while the manual control lever always is operable to enrich the fuel mixture and eliminate detonation, its effectiveness in the reverse direction is limited by the effect on engine operation, since the automatic control becomes operative when detonation conditions arise; to preclude manually setting the engine regulator beyond a position corresponding to a maximum allowable detonation severity.

The fixed type of control unit, as shown in Figs. 2 and 5, is mounted on a bracket 46 situated in fixed position with respect to the body of the engine. In the instance shown in Fig. 2, the unit is employed to initially retard the timed occurrence of ignition in the operation of the internal combustion engine. In this fully automatic arrangement, a pair of linked magnetos of conventional construction illustrated schematically at 63 are controlled from the unit 20 by the connecting link arm 64. The cyclic movement transmitting device or unit 20 operates in themanner previously described in response to the means for in a desired manner. In this instance, the carburetor includes a conventional air temperature controlling valve (not shown) which is automatically regulated by a unit through means of thepivotally mounted arm 65 and link 66. This form of utilization of the control device is slower in. response in overcoming detonation but is equally eifective.

Since many changes could be made in the above construction and many apparently widely different. embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and notin. a limiting sense.

What is claimed is:

1. The combination of an internal combustion engine having means for controlling its working conditions of operation, a linkage system by which said controlling means is positioned, means for detecting detonation in the cylinders of said engine, and cyclic actuating means included in said linkage system for automatically operating the controlling means for the engine responsive to said detonation detecting means.

2. The combination of elements claimed in claim 1, which includes means for controlling the time interval in which the return portion of the cycle of operation of said actuating means is effected.

3. The combination of elements claimed in claim 1, in which the means for controlling the engine is a carburetor having a valve positioned by said linkage system by which the ratio of fuel to air supplied the engine is regulated.

4. The combination of an internal combustion engine having a carburetor with a fuel regulating valve therein, a linkage system by which said regulating valve is manually positioned, means for detectin detonation in the cylinders of said engine, and a device, included in said linkage system, responsive to said detonation detecting means and operative to automatically change the position of said valve to control the engine.

5... A. device responsive to a detonation pick-up transmitter for controlling internal. combustion engines, comprising a cylinder element having two fluid containing. compartments, a piston ac-- tuating member for the device situated in said cylinder element, means responsive to the detonation pick-up transmitter, operable unidirectionally to supply fluid to one of said compart- -mentsand eifect movement of the piston actuating member, means for restoring the piston memberto an. initial position, and means for resisting the action of said restoring means, comprising a.

fluid restricting valve contair-iingv passageway which connects the fluid supplied compartment with the other compartment.

6. A device of thecharacter claimed-in claim.5,.

in which the compartments of the cylinder element are filled with; fluid, which. includes: pres-- sure responsive means for compensating for changes: in volume of thelfl-ui'd due. to. variances in temperature conditions in which the. device operates. w

7. A device of the character claimed in claim 5,

in which said unidirectionally operable" means is provided by a solenoid, energized by the detona-- tion pick-up transmitter, and a movable, fluid receiving, hollow core piece, cooperating with said solenoid, having a valve controlled passageway fluid to the piston member wall defined compartment and thereby effect movement of the piston member, means for restoring the piston member to an. initial position, a passageway for said cylinder element through which the fluid moves from said piston member wall defined compartment to said other compartment, and means situated in said passageway for controlling the: rateof movement of the fluid.

9. A device of the character claimed in claim 8, in which the electromagnetic means is provided by a solenoid, energized by the detonation pickup transmitter, and a movable fluid receiving, hollowing core piece, cooperating with said solenoid, which receives fluid from the other of said compartments and supplies fluid to the piston member wall defined compartment.

10. The combination of elements claimed in. claim 1, in which the means for controlling the working conditions of operation of the internal combustion engine is provided by an ignition timing control device, and the cyclic actuating means operate to initially retard the timed occurrence ing means in a manner tending to reduce the' occurrence of detonation.

12. A device for automaticallyoperating a positionable fuel-air mixture determining means associated with the carburetor of an internal combustion engine comprising a linkage system by which the mixture determining means is manually'positioned, means for detecting detonation. in a cylinder of the engine, and means operatively connected in said linkage system, responsive to saiddetecting means for automatically changing the position of the mixture determining means in a manner tending to reduce the occurrence of detonation.

13. A device for regulating an internal combustion engine, comprising means adapted. to control detonation occurring in said engine, manual means for setting said detonation control means in a desired operating position, and automatic means for modifying the: setting of said detonation control means in response to engine detonation.

14. A device for regulating an internal combustion engine, comprising means adapted to automatic control means including means for urging said detonation regulating means toward its original manual setting.

15. Detonation suppression apparatus for an internal combustion engine, comprising an engine regulator adapted when actuated to suppress detonation occurring in said engine, automatic control means responsive to engine detonation for actuating said engine regulator, manual control means for also actuating said engine regulator, and a warning indicator for showing when operation of said manual control means is required.

16. Automatic detonation suppression apparatus for an internal combustion engine of the type having an engine regulator operative to vary the detonation tendencies of said engine, said apparatus comprising a manual controller for said regulator, and automatic control means responsive to engine detonation for rendering said manual controller ineffectual to adjust said regulator in a manner to aggravate engine detonation when said detonation reaches a predetermined maximum level of severity.

17. Automatic detonation suppression apparatus for controlling a fuel-air mixture regulator of an internal combustion engine, comprising manually operable means for setting said regulator at a desired operating position, and automatic control means responsive to a predetermined intensity of detonation in said engine for limiting the minimum fuel-air ratio position of said regulator.

18. Detonation suppression apparatus for an internal combustion engine, comprising an engine 10 regulator operative to vary the detonation tendencies of said engine, automatic control means responsive to a predetermined maximum level of detonation severity to operate said regulator so as to suppress detonation, emergency manual control means operative on said regulator to eliminate detonation, and signal means for indicating when said automatic control means is inoperative.

19. An automatic detonation suppression apparatus for an internal combustion engine, comprising an engine regulator operative through a predetermined range to vary detonation tendencies in said engine, and an automatic controller responsive to each engine detonation of predetermined intensity for effectively adjusting said regulator by an amount corresponding to only a minor fraction of its effective range, in a direction to suppress detonation.

20. An automatic detonation suppression apparatus for an internal combustion engin comprising a fuel mixture regulator operative over a predetermined range to vary the detonation tendencies of said engine, and an automatic controller responsive to each engine detonation of at least a predetermined intensity for shifting said regulator a distance corresponding to a portion of its entire range in a direction to suppress detonation, said controller including escapement means for restoring said regulator to its original. position during a time interval substantially equal to the reciprocal of the desired incipient detonation frequency.

PHILIP. J. COSTA. 

